// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Data;
using Microsoft.Data.SqlClient;
 
namespace Microsoft.Extensions.Caching.SqlServer;
 
internal static class SqlParameterCollectionExtensions
{
    // For all values where the length is less than the below value, try setting the size of the
    // parameter for better performance.
    public const int DefaultValueColumnWidth = 8000;
 
    // Maximum size of a primary key column is 900 bytes (898 bytes from the key + 2 additional bytes required by
    // the Sql Server).
    public const int CacheItemIdColumnWidth = 449;
 
    public static SqlParameterCollection AddCacheItemId(this SqlParameterCollection parameters, string value)
    {
        return parameters.AddWithValue(Columns.Names.CacheItemId, SqlDbType.NVarChar, CacheItemIdColumnWidth, value);
    }
 
    public static SqlParameterCollection AddCacheItemValue(this SqlParameterCollection parameters, ArraySegment<byte> value)
    {
        if (value.Array is null) // null array (not really anticipating this, but...)
        {
            return parameters.AddWithValue(Columns.Names.CacheItemValue, SqlDbType.VarBinary, Array.Empty<byte>());
        }
 
        if (value.Count == 0)
        {
            // workaround for https://github.com/dotnet/SqlClient/issues/2465
            value = new([], 0, 0);
        }
 
        if (value.Offset == 0 & value.Count == value.Array!.Length) // right-sized array
        {
            if (value.Count < DefaultValueColumnWidth)
            {
                return parameters.AddWithValue(
                    Columns.Names.CacheItemValue,
                    SqlDbType.VarBinary,
                    DefaultValueColumnWidth, // send as varbinary(constantSize)
                    value.Array);
            }
            else
            {
                // do not mention the size
                return parameters.AddWithValue(Columns.Names.CacheItemValue, SqlDbType.VarBinary, value.Array);
            }
        }
        else // array fragment; set the Size and Offset accordingly
        {
            var p = new SqlParameter(Columns.Names.CacheItemValue, SqlDbType.VarBinary, value.Count);
            p.Value = value.Array;
            p.Offset = value.Offset;
            parameters.Add(p);
            return parameters;
        }
    }
 
    public static SqlParameterCollection AddSlidingExpirationInSeconds(
        this SqlParameterCollection parameters,
        TimeSpan? value)
    {
        if (value.HasValue)
        {
            return parameters.AddWithValue(
                Columns.Names.SlidingExpirationInSeconds, SqlDbType.BigInt, value.Value.TotalSeconds);
        }
        else
        {
            return parameters.AddWithValue(Columns.Names.SlidingExpirationInSeconds, SqlDbType.BigInt, DBNull.Value);
        }
    }
 
    public static SqlParameterCollection AddAbsoluteExpiration(
        this SqlParameterCollection parameters,
        DateTimeOffset? utcTime)
    {
        if (utcTime.HasValue)
        {
            return parameters.AddWithValue(
                Columns.Names.AbsoluteExpiration, SqlDbType.DateTimeOffset, utcTime.Value);
        }
        else
        {
            return parameters.AddWithValue(
                Columns.Names.AbsoluteExpiration, SqlDbType.DateTimeOffset, DBNull.Value);
        }
    }
 
    public static SqlParameterCollection AddWithValue(
        this SqlParameterCollection parameters,
        string parameterName,
        SqlDbType dbType,
        object? value)
    {
        var parameter = new SqlParameter(parameterName, dbType);
        parameter.Value = value;
        parameters.Add(parameter);
        parameter.ResetSqlDbType();
        return parameters;
    }
 
    public static SqlParameterCollection AddWithValue(
        this SqlParameterCollection parameters,
        string parameterName,
        SqlDbType dbType,
        int size,
        object? value)
    {
        var parameter = new SqlParameter(parameterName, dbType, size);
        parameter.Value = value;
        parameters.Add(parameter);
        parameter.ResetSqlDbType();
        return parameters;
    }
}